<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box {
            width: 100px;
            height: 100px;
            padding: 100px;
            border: 5px solid #000;
            margin: 100px auto;
            /*将一个盒子开启3d空间，需求配合景深来使用*/
            transform-style: preserve-3d;
            /*景深，近大远小*/
            perspective: 100px;
            perspective: 800px;
        }

        .child {
            width: 100px;
            height: 100px;
            background: red;
            transition: 1s;
        }

        .box:hover .child {
            transform: translateZ(400px);

        }
    </style>
</head>
<body>
<div class="box">
    <div class="child">lang</div>
</div>
</body>
</html>